Closure for bottle

ABSTRACT

A closure for a flexible bottle made of polyethylene or other material having similar physical properties. The closure and the bottle are shaped so that when the closure is screwed onto the neck of the bottle sealing occurs between the closure and the bottles at the end surface of the neck and at the inner and outer edges of the upper end of the neck.

Umted States Patent 1 1 1 1 3,727,784

Sargent 1 1 Apr. 17, 1973 1 1 CLOSURE FOR BOTTLE 3,428,208 2/1969 Kosar ..2 15/010. 1

3,595,418 7/1971 Adcock et a] ..215/43 R X [75] Inventor: Frank Sargent Nmeamm 3,433,3s0 3/l969 Kawchitch ..215/43 R x gland 3,335,923 8/1967 Healy ..21'5/40 ux [73] Assignee: Thetford Corporation, Ann Arbor,

i Primary ExaminerDonald F. Norton Attorney-Olsen and Stephenson [22] F1led: Oct. 20, 1971 211 Appl. No.: 191,021 1 1 ABSTRACT A closure for a flexible bottle made of polyethylene or 521 US. Cl ..21s/40, 150/5, 215/43 R, other material having Similar P y p p e The 215/[ 1 closure and the bottle are shaped so that when the clo- [51] Int. Cl. ..B65d 41/04 re i r w onto the neck of the bottle sealing 0c [58] Field of Search ..215/1 C, 40, 41, r e n he cl sure n the bottles at the end 215/43 R, DIG, 1; 150/,5 surface of the neck and at the inner and outer edges of the'upper end of the neck. [56] References Cited 4 Cla ms, 3 Drawing Figures PATENTEBAPR 1 H975 INVENTOR FRANK T. SARGENT ATTORNEYS CLOSURE FOR BOTTLE BACKGROUND OF THE INVENTION The present invention relates to a closure for a bottle which will seal the contents of the bottle as an incident to securing the closure in place on the bottle.

One of the problems that exists with respect to plastic'containers or bottles used to store liquid contents is that of .producing economically a bottle and closure or cap which provides satisfactory liquid seal. This is especially true in the field of recreational equipment where bottles of liquid supplies are transported in a manner which may readily cause leakage of the contents if inadequate seals are provided. It is common practice to insert a sealing element 'in the cap or between the cap and bottle, but such arrangements require the manufacture of a separate seal element which adds to the cost of the products, and further, when the cap is repeatedly removed to use some of the contents, the seal often is lost. These and other problems have created a continuing need for an improved cap and bottle combination which is characterized by the low costof the bottle and cap and the effectiveness of the seal provided. I

SUMMARY OF THE INVENTION The present invention has overcome the inadequacies of the prior art so that a very effective seal is provided between the bottle and the cap merely as incident of screwing the cap in place on the neck of the bottle. This is done by stressing the neck of the bottle when applying the cap or closure so that the neck in cooperation with the cap will provide a plurality of seal engagement surfaces to prevent leakage of the contents of the bottle.

According to a preferred form of the present invention a combination of cap' and bottle is provided wherein the bottle is formed from a flexible material such as polyethylene, and it has a neck that includes an externally threaded portion and a generally annular portion located above the threaded portion and defining the outlet of the bottle. The outlet end of the neck has an upper wall with radially inner and outer edges in space relation, and a closure or cap for the bottle is provided comprising a top wall with annular rib on its lower surface and a circular side wall space radially outward of the annular rib. The side wall of the cap includes an internally threaded lower portion in engagement with the threaded portion of the bottle, and an inwardly converging portion extending above the threaded lower portion and said top wall of the cap. The smallest diameter of the inwardly converging portion is less than the external diameter of the outer edge ofthe upper wall of the neck, measured when the bottle is in the unstressed condition. Thus, when the closure is screwed onto the bottle the annular portion of the bottle will be constricted between the inwardly converging portion and the annular rib to provide sealing engagement between the cap and the bottle at the outer and inner edges of the neck as well as at the top surface of the neck of the bottle.

In the preferred embodiment, the wall thickness of the neck when in its unstressed condition is greater than the spacing between the side wall and and the annular rib of the cap so that when the cap is screwed onto the neck of the bottle the wall of the bottle will be squeezed so as to provide tight sealing engagement at the outer and inner edges as well as along the top surface of the bottle which will bulge upwardly as a result of the squeezing action to sealing engage the under surface of the cap.

Thus, it is one of the objects of the present invention to provide an improved bottle and closure cap therefore which is constructed and arranged to provide an effective seal for liquid contents thereof.

Other objects of this invention will appear in the fol lowing description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

IN THE DRAWING FIG. 1 is'a fragmentary sectional view of a bottle and a closure therefore embodying features of the present invention;

FIG. 2 is an exploded view showing the bottle in its unstressed condition and the cap in readiness for securing it to the bottle; and

FIG. 3 is an enlarged view showing a portion of the closure and showing in broken lines the shape of the bottle in its unstressed condition with respect to the closure.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in' the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carries out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, the invention will be described in greater detail. The bottle 10 is preferably made of polyethylene plastic material, and it has a neck 12 that includes an externally threaded portion 14 and a generally annular or cylindrical portion 16 located above the threaded portion and defining the outlet end 18 of the bottle. The outlet end 18 has an upper wall 20 with radially inner and outer edges 22 and 24 in space relation.

' The cap or closure 26 has a top wall 28 with an annular rib 30 on its lower surface 32. The closure 26 also has a circular side wall 34 that is spaced radially outward from the annular rib 30. The side wall 34 includes an internally threaded portion 36 which is adapted for threaded engagement with the externally threaded portion 14 of bottle 10. The side wall 34 also includes an inwardly converging portion 38 extending between the threaded lower portion 36 and the top wall 28. As seen best in FIG. 3, the inwardly converging portion 38 defines a frustoconical surface originating at the upper end and at the radially inner extremity of the threaded lower portion 36. The annular rib 30 has a radially outer surface 40 that diverges outwardly and upwardly until it intersects the lower surface 32 of the top wall 28. The intersection of the surface 40 with the top wall 28 and the intersection of the inwardly converging portion 38 with the top wall 28 are radially spaced to provide a relatively narrow annular surface 42 which has a smaller radial dimension than the thickness of the wall of the neck 12 of bottle 10.

As can be seen in FIG. 3, when the bottle is in its unstressed condition the outer edge 24 has a greater diameter than the smallest diameter of the inwardly converging portion 38. Likewise, the diameter of the inner edge 22 is less than the largest diameter of the outwardly diverging surface 40. Thus, when the cap is screwed onto the bottle 10, the upper end of the generally annular portion 16 will be compressed inwardly and the upper corner 22 will be urged outwardly so that the upper end of the bottle will be squeezed together causing the material of the bottle to flow to make contact with the annular surface 42. Forces will be applied to the flexible bottle 10 in the direction of the arrows A, B and C in FlG. 1 to provide seals along the corners or edges 22 and 24 as well as between the top wall of the bottle and the surface 42 of the cap 26.

From the foregoing it will be recognized that a very effective seal has been provided which will prevent leakage of fluids from the bottle 10 even when subjected to severe handling conditions. The bottle and cap can be manufactured in the normal manner so as to maintain cost at a minimum.

It is claimed:

1. in combination, a flexible bottle having a neck that includes an externally threadedportion and a cylindrical portion located above 'the threaded portion and defining the outlet of the bottle, the outlet end of the neck having an upper wall with radially inner and outer edges in spaced relation, and a closure for said bottle comprising a top wall with an annular rib on its lower surface and a circular side wall spaced radially outward of said annular rib, said side wall including an internally threaded lower portion in threaded engagement with the threaded portion of said bottle and an inwardly converging portion extending between said threaded lower portion and said top wall, said inwardly converging portion being a frusto-conical surface originating at the upper end and at the radially inner extremity of said threaded lower portion, the smallest diameter of said inwardly converging portion being less than the external diameter of said outer edge of said upper wall in the unstressed state of said bottle so that when the closure is screwed onto the bottle the annular portion of the bottle will be constricted radially inwardly by said inwardly converging portion and into engagement with said annular rib.

2. The combination that is defined in claim 1, wherein the radial dimension at said top wall between said annular rib and said inwardly converging portion is less than the radial dimension between said inner and outer edges of said neck so that screwing the closure fully onto the bottle will squeeze the inner and outer surfaces of the neck together causing the upper wall thereof to bulge into sealing relation with the top wall of said closure.

3. Thecombination that is defined in claim 2, wherein said annular rib has a radially outer surface that diverges outwardly until it intersects said top wall.

4. The combination that is defined in claim 1, wherein said annular rib has a radially outer surface that diverges outwardly until it intersects said top wall,

the lar est diameter of said Outersu rface being greater than t e internal diameter of said inner edge of said upper wall in the unstressed state of said bottle. 

1. In combination, a flexible bottle having a neck that includes an externally threaded portion and a cylindrical portion located above the threaded portion and defining the outlet of the bottle, the outlet end of the neck having an upper wall with radially inner and outer edges in spaced relation, and a closure for said bottle comprising a top wall with an annular rib on its lower surface and a circular side wall spaced radially outward of said annular rib, said side wall including an internally threaded lower portion in threaded engagement with the threaded portion of said bottle and an inwardly converging portion extending between said threaded lower portion and said top wall, said inwardly converging portion being a frusto-conical surface originating at the upper end and at the radially inner extremity of said threaded lower portion, the smallest diameter of said inwardly converging portion being less than the external diameter of said outer edge of said upper wall in the unstressed state of said bottle so that when the closure is screwed onto the bottle the annular portion of the bottle will be constricted radially inwardly by said inwardly converging portion and into engagement with said annular rib.
 2. The combination that is defined in claim 1, wherein the radial dimension at said top wall between said annular rib and said inwardly converging portion is less than the radial dimension between said inner and outer edges of said neck so that screwing the closure fully onto the bottle will squeeze the inner and outer surfaces of the neck together causing the upper wall thereof to bulge into sealing relation with the top wall of said closure.
 3. The combination that is defined in claim 2, wherein said annular rib has a radially outer surface that diverges outwardly until it intersects said top wall.
 4. The combination that is defined in claim 1, wherein said annular rib has a radially outer surface that diverges outwardly until it intersects said top wall, the largest diameter of said outer surface being greater than the internal diameter of said inner edge of said upper wall in the unstressed state of said bottle. 